<template>
  <div class="helper">
    <span class="left">{{unFinishedTodoLength}} items left</span>
    <span class="tabs">
      <span v-for="state in states" :key="state" :class="[state, filter === state ? 'actived' : '']" @click="toggleFilter(state)">
        {{state}}
      </span>
    </span>
    <span class="clear" @click="clearAllCompleted">clear completed</span>
  </div>
</template>
<script>
export default {
  props: {
    todos: {
      type: Array,
      required: true
    },
    filter: {
      type: String,
      required: true
    }
  },
  data () {
    return {
      states: ['all', 'active', 'completed']
    }
  },
  computed: {
    unFinishedTodoLength () {
      return this.todos.filter(todo => !todo.completed).length
    }
  },
  methods: {
    toggleFilter (state) {
      this.$emit('toggle', state)
    },
    clearAllCompleted () {
      this.$emit('clearAll')
    }
  }
}
</script>
<style lang="stylus" scoped>
 .helper{
        font-weight 100
        display flex
        justify-content space-between
        padding 5px 0
        line-height 30px
        background-color #ffffff
        font-size 14px
        font-smoothing:antialiased;
    }
    .left,.clear,.tabs{
        padding 0px 10px
        box-sizing border-box
    }
    .left,.clear{
        width 150px
    }
    .left{
        text-align left
    }
    .clear {
        text-align:right
        cursor pointer
    }
    .tabs{
        width 200px
        display flex
        justify-content space-around
        *{
            display inline-block
            padding 0px 10px
            cursor pointer
            border 1px solid rgba(175,47,47,0)
            &.actived{
                border-color rgba(175,47,47,0.4)
                border-radius 5px
            }
        }
    }
</style>

